Graphite is s superb and flexible medium for field sketching. To get more out of your pencil, experiment with these key ideas.
Try a softer lead
Your pencil drawing will improve if you increase its value range (light to dark). The standard #2 or HB pencil is too hard to create rich darks. Switch to a softer lead to allow you to push your dark values. I fill my mechanical pencils with 2B lead, a good default.
Fill areas of tone with a dull pencil or chiseled tip
It takes a long time to fill a shape with tone using a sharp pencil or a .5 or smaller mechanical pencil. Try a dull pencil with a broader tip. As you draw with it, one surface will flatten to a chisel shape as you wear the pencil down. Keep using this flat surface to fill the shape instead of rotting the pencil to the sharp edge. If you like using mechanical pencils, try a .7 mm pencil for broader lines. If you need to click the pencil to advance the lead but want to keep using the broad chiseled surface you have created with your shading, maintain your grip and press the back of the pencil against your chest.
Use a blending tool
Use a paper blending tool both to flatten and smooth areas of tone and to “paint” light values with graphite. Blending also creates a solid toned background against which you can erase positive shapes. Which leads us to…
Draw with your eraser
Use a kneaded eraser to lighten parts of your drawing without smudging. Try tapping or pressing the eraser on the paper to lift out graphite in a controlled way. You also can draw in white elements with a fine point eraser such as the Mono Zero.
Protect your work with fixative
If you draw with soft lead, your drawings will be more vulnerable to smudging, particularly if you use a spiral bound (vs. sewn in binding) sketchbook. Therefore, regular spray your sketches with fixative to preserve your work.
Lets look at how these ideas come into play with a sketch of rising mist in Yosemite Valley. Click on the first image to start a step by step side-show.